1. Field of the Invention
The present invention relates to an automotive electric power unit for supplying electric power to components of a vehicle.
2. Related Art
EV (Electric Vehicles) or HEV (Hybrid Electric Vehicles) are usually equipped with a DC/DC converter converting a voltage higher than 12 volts of a high voltage battery into a lower voltage so that electric power is supplied to power units for a control computer for the vehicle as well as auxiliary machineries such as cooling fans, air conditioners, and fuel pumps. To the output terminals of the DC/DC converter, besides a battery, various auxiliary machineries such as a cooling fan, an air conditioner, and a fuel pump are connected in parallel in such a way that the DC/DC converter and the auxiliary machineries or equipment are switched off at the same instant when a n ignition switch for actuating the vehicle is turned off.
As described in JP-A-2001-239902, while monitoring the remaining power in a battery, also in an idling vehicle, vehicle-mounted auxiliary machineries i.e. “power loads” may be actuated by the power of a high voltage battery, when the remaining power of the high voltage battery is large enough to activate a motor starter.